MIT-Curricular/DS/C/Lab/Week3/Parenthesis.c

#include <stdio.h>
#include <string.h>

#define MAX_SIZE 100

int top = -1;
char stack[MAX_SIZE];

void push(char value) {
    if (top == MAX_SIZE - 1) {
        printf("Stack is full\n");
        return;
    }
    stack[++top] = value;
}

char pop() {
    if (top == -1) {
        printf("Stack is empty\n");
        return '\0';
    }
    return stack[top--];
}

int isMatching(char c1, char c2) {
    if (c1 == '(' && c2 == ')')
        return 1;
    if (c1 == '[' && c2 == ']')
        return 1;
    if (c1 == '{' && c2 == '}')
        return 1;
    return 0;
}

int isParenthesisBalanced(char* expression) {
    for (int i = 0; i < strlen(expression); i++) {
        char c = expression[i];

        if (c == '(' || c == '[' || c == '{')
            push(c);

        if (c == ')' || c == ']' || c == '}') {
            char pop_value = pop();

            if (!isMatching(pop_value, c))
                return 0;
        }
    }

    if (top == -1)
        return 1;
    else
        return 0;
}

int main() {
    char expression[MAX_SIZE];
    printf("Enter an expression: ");
    scanf("%s", expression);

    if (isParenthesisBalanced(expression))
        printf("Expression is balanced\n");
    else
        printf("Expression is not balanced\n");

    return 0;
}